After the smoothning I added some more of the dark colors from my palette.
I personally think that painting the edge where the skin goes in to shadow was the most challenging aspect of this painting. A 'broad' edge makes the impression of a round form, while a short, contrasted edge forms a sharp edge.
Also, be careful not to mix black into the midtones. This will give a gray gradient like the 3-color Photoshop gradient seen above in this lesson. To avoid this use at least 3 of the darker colors in the palette as the skin moves in to shadow.

left: some of the difficult shadow areas are refined with more brown to avoide "gray-look";
right: smoothed

Left: left breast refined, working on the lower-arm; middle/right: working on the hand